On-site Visualization of Solar Power Design Data with AR | Construction Simulation Realized by LRTK

Introduction: the gap between solar power project design and the field

In large-scale solar power projects, there are often gaps between carefully prepared design drawings and the actual site. Slight differences in terrain, misinterpretation of drawings, and lack of communication can lead to cases where construction cannot proceed exactly as designed. As a result, sudden design changes or rework can occur on site, causing schedule delays and additional costs.

Designers perform optimal layouts and generation simulations at their desks, but those results do not always match on-site conditions 100%. For field construction managers, relying only on paper drawings and coordinate lists to accurately stake out positions across a vast site is a major burden. For example, a location assumed to be flat in the design phase may actually have a gentle slope requiring adjustment of rack heights, or temporary stakes indicating pile positions may be off and later require correction.

How can we close these "design-to-site gaps" and ensure smoother construction? This article introduces AR (augmented reality) technology and construction simulation using LRTK as a promising solution.

Why AR (Augmented Reality) is needed on construction sites

AR (Augmented Reality) technology has emerged as a means to bridge the gap between site and design. AR overlays digital 3D information onto the real landscape, and with recent improvements in smartphone and tablet performance, it has become practical for use on construction sites. The latest iPhones and iPads, in particular, are equipped with high-performance cameras and LiDAR sensors, and dedicated apps that utilize these features now make it possible to incorporate AR into everyday construction management. As the industry-wide DX (digital transformation) is promoted through initiatives such as the MLIT-led i-Construction, AR—which can directly link drawing information to the actual site—is attracting attention as a powerful solution that can simultaneously improve site efficiency and quality.

Why is AR sought after for construction sites like solar power plants? The primary reason is that intuitive on-site visualization resolves gaps. Things that look fine on drawings may reveal issues when viewed in the actual terrain or environment. With AR, you can intuitively grasp those discrepancies on the spot before or during construction, enabling early detection of problem areas. Even inexperienced workers can immediately understand the completed image and precise installation positions displayed in AR, reducing communication loss and human error. Processes that previously required surveying, returning to the office, and comparing with drawings can now be verified and decided on-site with AR. In expansive sites such as solar power plants, simply matching drawings to the site used to take significant time, but AR enables "checking while viewing on-site," greatly improving work efficiency. For these reasons, demand for AR adoption on construction sites is increasing.

How LRTK provides AR visualization

What specific mechanisms are needed to utilize AR on site? A key solution is LRTK, provided by Lefixea. LRTK is a system that enables centimeter-level positioning by attaching a compact high-precision GNSS receiver to a smartphone. It uses RTK (Real Time Kinematic) satellite positioning augmentation technology to obtain highly accurate position information in real time, with errors within a few centimeters (a few inches). By using this high-precision position information for AR display, design data 3D models can be projected into the real world without noticeable misalignment.

Conventional smartphone AR typically involves an initial manual alignment between the virtual model and the real object on site (origin alignment), followed by position tracking using the device's accelerometer and camera feature-point tracking. However, this method suffers from model drift as the user moves. In contrast, LRTK continuously supplements model position with absolute coordinates from GNSS, so once a 3D model is displayed it rarely shifts as the user moves. Initial alignment is also performed automatically, allowing immediate AR use on site without complicated calibration work.

For example, when projecting a solar panel rack model onto the site scenery, LRTK displays it at the correct position and scale based on coordinates obtained from the design drawings, so it appears to match the actual ground exactly. The model's orientation also follows the direction the camera is pointed in real time, allowing users to walk around and inspect from various angles without discomfort. LRTK also provides mechanisms to share and manage the obtained high-precision positioning data and point-cloud scan data in the cloud, facilitating data linkage between the site and the office. LRTK can thus be described as an AR visualization platform that bridges design data and the site with high precision and seamless integration.

Practical benefits of visualizing design data on site

What benefits does on-site visualization of design information bring to site management? Here are the main advantages.

• Immediate issue detection and correction: Because you can overlay the design model on site and check it against reality, you can discover problems during construction and immediately consider corrective measures. For example, if "the pile was supposedly driven according to the drawings but in fact the position was off," AR allows you to notice and correct it instantly. This prevents situations where mistakes are discovered after concrete casting and rework becomes necessary.

• Improved construction accuracy and quality: Following AR guides aligned with centimeter-level accuracy (half-inch accuracy) minimizes deviations from design coordinates. All equipment can be installed at the planned positions, angles, and heights, improving overall plant quality and safety. This is especially reassuring for solar foundations requiring many piles, where cumulative deviations of individual pile positions can cause rack distortion or uneven panels; AR prevents such issues.

• Dramatic improvement in work efficiency: Compared to traditional methods of holding drawings and using surveying equipment to stake points, AR work—following intuitive camera-guided instructions—is far faster. Tasks that previously required a surveying team for each point can be completed by one person walking with a smartphone. In fact, there are reports that stake positioning using RTK-GNSS and AR was completed in approximately 1/6 of the time required by conventional optical surveying methods. Such time savings significantly boost overall site productivity.

• Smoother communication: Showing the AR screen on a smartphone or tablet to stakeholders on site allows anyone to intuitively understand the completed form. Designers, constructors, and clients can communicate more easily than when reading drawings. Visual explanations help those unfamiliar with technical terms or drawing symbols, reducing miscommunications and misunderstandings and making meetings more efficient.

• Addressing labor shortages and skills transfer: Even without seasoned experts on site, accurate construction is possible by following AR guidance, so less experienced staff become productive. Staff without surveying expertise can perform staking tasks simply by following instructions on the smartphone screen. Tasks that previously required scheduling surveyors can be handled by on-site personnel, making it easier to cope with labor shortages. Digital tools supplement areas that relied on veteran intuition and experience, helping bridge the skills transfer gap.

• Cost reduction: Preventing rework and shortening working time ultimately compress construction costs. Replacing expensive dedicated surveying equipment with a handheld smartphone reduces equipment purchase and rental expenses. Efficiency gains also lower labor costs and shorten schedules, producing significant overall cost benefits.

Use cases: verifying pile locations / previewing rack installation / schedule meetings

How can AR visualization be applied in specific scenarios on a solar power site? Here are representative use cases.

• Verifying pile positions: To support solar panel racks, hundreds of piles must be accurately placed across a wide site. With LRTK's AR guidance, workers carrying a smartphone are navigated to each design-specified pile location. As they approach the target point, a crosshair or similar mark appears on the screen indicating "this is the pile location," allowing the point to be identified with an accuracy of only a few centimeters (a few inches). Workers can mark the spot and then drive the pile with a pile driver, which is vastly faster and more reliable than the traditional method of using tape measures and surveying instruments for each pile. Even in complex terrain where you cannot physically stand on the pile location, AR can display a virtual pile to indicate "there is a pile at this position," enabling safe and accurate position identification on steep slopes.

• Previewing rack installation images: Overlaying a 3D model of the rack onto the site scenery with AR lets you grasp the post-construction appearance and layout balance in advance. For example, when arranging racks on a slope, AR allows visual confirmation of differences in heights and angles among racks, revealing inconsistencies that might be hard to notice at the design stage. You can also check for interference with the terrain (whether a rack leg would be buried too deeply or conversely float too much) and consider adjustments to pile length or support methods. Displaying how solar panels will actually be arranged via AR is also useful for explaining visual impact to neighbors and sharing the completed image with stakeholders.

• Use in schedule meetings: AR is also valuable in on-site schedule meetings and planning sessions. By projecting uninstalled equipment models or items planned for the next stage onto the site with a smartphone or tablet, all participants can discuss specifics while looking at the same projected completion image. Spatial plans that are hard to convey with paper schedules or drawings—such as "which area to construct next" or "where to bury this cable"—become immediately clear on the AR screen. This improves alignment on work procedures and responsibilities, shortens meeting times, and prevents mistakes. Sharing the future completed form through AR can also boost team motivation.

How to prevent common "design-to-construction deviations" in solar power projects

Deviations between design and construction stages in solar installations can lead to major issues in later processes. However, using AR and digital surveying technologies makes it possible to prevent such deviations in advance. Here are some key countermeasures.

• On-site AR verification before construction: Before starting work, bring the design data to the site and project the completed model and layout in AR. Plans that looked fine on drawings may reveal surprises when overlaid on the actual terrain. AR helps identify problems, especially near boundaries or in areas with elevation differences. For example, you can verify whether "a panel row is too close to a neighboring boundary" or "the rack leg length for a steep slope is sufficient," and make design corrections before construction starts. This simple step greatly reduces the risk of later design changes.

• Accurate position guidance with AR: During construction, use AR guidance with RTK-GNSS-compatible systems like LRTK to accurately perform piling and equipment installation. This minimizes manual surveying errors and transmission mistakes, enabling construction that closely matches design coordinates. If components are initially positioned at the correct coordinates and angles, time-consuming adjustments and rework are reduced. For repetitive piling tasks typical in solar projects, AR guidance ensures that "anyone can place piles with the same accuracy," preventing quality variability.

• Ongoing checks during construction: As work progresses, periodically overlay the partially completed structures with the design model in AR for verification. For example, after piling is completed, compare the actual pile positions with design positions in AR to check for deviations. If small discrepancies are found, corrections can be made at that stage to prevent impacts on subsequent steps. For buried piping work, verifying alignment with the design before backfilling using AR prevents recording errors or overlooked defects. Incorporating AR checks into the construction sequence helps stop deviations from developing into major issues.

• Digital records and feedback: Use a surveying app integrated with AR to save and share construction data captured on site to the cloud in real time. Office designers can immediately grasp measured on-site values and quickly notice differences between design and reality. For example, using LRTK's point-cloud scan function to record post-construction terrain or structures as 3D data and color-compare them with the design model lets you visually analyze elevation differences and position deviations on the order of a few centimeters (a few inches). Differences detected in this way can be used not only for reports but also to improve future designs. Feedback of real on-site insights helps build mechanisms to avoid repeating the same deviations in future solar projects.

AR display operability and usable scope (smartphone devices, coordinate data, on-site environment)

To maximize the effectiveness of AR on site, consider a few points regarding equipment and environment.

• Ease of use with a single smartphone: No special equipment is required for AR display—you can use the smartphones and tablets already used daily on site. Modern iPhones and Android devices come standard with high-performance AR features, and attaching a compact GNSS receiver like LRTK can ensure positioning accuracy. Because everyone is familiar with smartphone screens, AR adoption on site faces little resistance and is intuitive to operate. Applications also include scenarios such as machine operators checking a tablet from the cab; the scope of AR use is not limited to a single smartphone.

• Integration with design coordinate data: Correct AR display requires design data to include location coordinate information. When preparing plan drawings (DXF/DWG, etc.) or 3D models, align them as much as possible with the real-world survey coordinate system. For example, if models are created with WGS84 latitude/longitude or plane rectangular coordinates and uploaded to the cloud, the LRTK app will automatically overlay them at the correct on-site positions. If only a proprietary local coordinate system exists, you can still work around this by measuring known reference points on site and aligning them. The bottom line is that accurate AR display is achievable without complicated manual positioning as long as the digital design data and site survey coordinates match.

• Outdoor environment precautions: When using AR on outdoor sites like solar power plants, be mindful of surrounding environmental conditions. GNSS positioning performs best in open-sky locations; accuracy can degrade or positioning may fail in areas where satellite signals are blocked by forests, cliffs, or similar obstructions. In such cases, combining conventional survey methods based on optical distance measurement or temporarily placing ground reference markers to align AR models can be effective. Also, in direct sunlight during summer, smartphone screens can be hard to see—improve visibility by securing shade or fitting a tablet hood. Although the setup is a smartphone plus GNSS receiver, these are still precision devices, so it is important to take precautions such as using waterproof/dustproof cases, attaching a drop-prevention strap, and preparing spare batteries for long operation. Preparing in advance ensures reliable operation even under harsh site conditions.

Field voices: faster on-site decision-making thanks to AR

On sites that have introduced AR technology, many report that "decision-making on construction sites has become markedly faster." One construction manager for a solar plant said, "Because I can confirm on-site via AR whether equipment is placed according to the drawings, I can make immediate decisions and proceed to the next stage." Eliminating the need to compare drawings with actual conditions has reduced downtime when workers would otherwise wait for decisions. Another site supervisor commented that "meetings that used to involve discussing paper drawings now proceed much faster thanks to AR, since everyone can more easily visualize the completed form." Even in cases where surveying results were previously taken back to the office for consultation with designers, AR enables everyone to gather on-site virtually and understand the situation, allowing "decisions to be made the same day" and reducing wasted waiting time. In this way, AR accelerates on-site judgment and communication, contributing to overall project speed-up.

Conclusion: making solar construction smarter with AR + positioning technologies

The combination of AR and high-precision positioning technology is bringing unprecedented "smart construction" to solar power plant sites. As seen in this article, AR is a very powerful solution for closing the information gap between design and site and achieving accurate, efficient, and safe construction. Using systems like LRTK makes it possible to visualize design models on site with just a smartphone instead of relying on dedicated equipment, significantly changing site management practices. By supporting and automating tasks that previously depended on manual effort and experience, digital technology helps everyone proceed without mistakes, improving productivity and reducing risk across the project. As solar power projects expand, smart construction using AR + positioning technologies will increasingly become the standard approach. Riding the wave of site DX, we should actively adopt AR technology to achieve smarter and more resilient solar construction.

For those considering using LRTK's AR features and simple surveying

Finally, here are points to consider for those thinking about introducing LRTK's AR features and smartphone surveying in their own organizations.

• Prepare digital design data: As the first step in AR utilization, digitize drawings and models (prepare CAD data and 3D models). Ideally, prepare 3D models with coordinate information (BIM/CIM, etc.) from the design stage. Even without 3D data, AR display is possible if a plan drawing includes coordinates for key points, so start by organizing basic information such as a list of pile positions.

• Start small with a pilot: If you are hesitant to deploy site-wide immediately, begin by testing AR on a limited area or specific task. For example, try AR guidance for piling on a small rack row to let the team experience the efficiency gains. Starting with a small pilot and expanding the application scope once benefits are realized helps site staff adapt smoothly.

• Train site staff: Provide short operation briefings or demo sessions for staff unfamiliar with smartphone or AR operation. Fortunately, the LRTK app has a simple interface with Japanese support, and once used, its convenience becomes intuitive. If there are concerns, have veterans and newcomers perform the first few staking tasks together while viewing AR, to help newcomers learn. Sharing AR visuals site-wide can spark ideas for other use cases.

• Utilize the LRTK solution: LRTK is an integrated solution combining positioning devices, a smartphone app, and cloud services, allowing you to procure the necessary equipment and software in a single package. While traditional centimeter-class surveying equipment (RTK-GNSS receivers, total stations, etc.) used to cost several hundred thousand dollars, LRTK dramatically lowers the introduction hurdle, making it accessible to small and medium-sized businesses. Because it leverages existing smartphones, the burden of learning new hardware is minimal. For more details and case studies, please refer to the [LRTK official site](https://www.lrtk.lefixea.com) to assess applicability to your projects.

For product inquiries or consultation on introduction, feel free to contact us via [Contact](https://www.lrtk.lefixea.com/contactlrtk). Let cutting-edge technology take your solar power plant construction process to the next stage.